NICE QUESTION...............
SEE DA ORIGIN WILL BE DA MP.......
.SO HALF OSSILATION ON RIGHT AND HALF OSSILATION ON LEFT OF DA GRAPH IS COMPLETED IN 1 FULL OSSILATION!!!!!!!!!!!!!!!!!!!!
IN LEFT HAND SIDE dU/dx = F =kx=mw^2x...........................so w = root(k/m).....
hence time period is piroot(m/k).....(note its not 2 pi cuz its only half ossicilation!!!!!!!!!!!!!!!!!!)
on the right hand side it is similar to throwing a ball against gravity(as u can see dU/dx=mg
......at da origin KE= E.......so v^2 = 2E/m
....2v/g will be da time to rise and cum back to mean pos
........so 2root(2E/mg^2 is da other half of da time periiod
add both its the full time period...